3 Maternal Testing Part 2 Flashcards
What does CVS stand for?
Chorionic villi sampling (CVS)
What are 2 exams performed for CVS
Transcervical
Transabdominal
Transcervical CVS is performed between __ and __ weeks
11 and 12.5 weeks
Catheter is inserted through cervix to the?
chorion frondosum
With ______________from syringe moving catheter back and forth will capture the chorionic villi cells.
negative pressure
With the transabdominal approach a needle passes through the ________to the chorion frondosum
abdomen
Performed when placenta cannot be accessed by Transcervical and can be done beyond
12.5 weeks
Method of transcervical or transabdominal depends on there the _____ lies
placenta (chorion frondosum)
More DNA is obtained from a ___ than a _____
CVS; amniocentesis
Which has Faster/earlier results a CVS or amniocentesis
CVS
CVS has 1/200 risk for
spontaneous abortion
CVS cannot detect NTD, but _____ & ____
Chromosomal abnormalities and DNA
CVS can cause(2)
PROM
infection
If CVS is positive patient sent for
genetic counselling
Amniocentesis uses the transabdominal approach (needle through moms abdomen) to look at ?
Amniotic fluid from amniotic sac
Amniocentesis detects (3)
chromosomal abnormalities
NTD
and some genetic disorders
Amniocentesis completed for 3 reasons
genetic testing
fetal lung testing
for treatment of ployhydramnios
The risks of Amniocentesis include (4)
Bleeding
PROM
Preterm labour
Club feet
When is optimal time to perform Amniocentesis?
16 weeks and onwards
What does the Radiologist need to know from us before performing an Amniocentesis (4)
of fetuses
position of fetuses
Placental location
Gestational age - BPD, HC, AC, FL
The _____ with ____ is taken before and after the procedure.
Heart rate; m mode
A limited anatomical survey is done before the Amniocentesis which includes
choroids, fetal heart, stomach, bladder, kidneys, spine, limbs
Amniocentesis is a sterile technique using (6)
Needle (16,18,20 gage) syringe cleaning solution poured into vials (betadine brown) (alcohol pink) Bx guide (biopsy guide for needle) sterile gel probe cover (all the way up the cord)
What is considered not sterile (2)
Sonographer and the machine
What artifacts can be seen with Amniocentesis that can distort the needle position
Refraction and reverberation
How many CC’s of amniotic fluid is aspirated into each syringe?
10 CC’s
The amniotic fluid is then emptied into 2______ vials
non sterile
What are the difference types of Amniocentesis (4)
Cytogenetic Amniocentesis
O.DD (optical density Determination)
L/S Amniocentesis
Therapeutic
Cytogenetic Amniocentesis is when _______ from the amniotic fluid is cultured for analysis.
fetal skin cells.
DNA and biochemistry (AFP) is looked at
When can a Cytogenetic Amniocentesis be performed?
11 weeks to term
Abnormalitites at ___ weeks will require a amnio for fetal chromosomes
18 week (detailed scan)
Cytogenetic Amniocentesis is routinely done in these cases (3)
Late maternal age
Hx of congenital abnormality
previous pregnancy or direct relative
Twin Amniocentesis uses dye to differentiate the 2 gestational sacs called.
INDIGO CARMINE* (TWIN A)
If the doctor draws purple dye then they have pulled ?
Twin A
Non purple (Twin B)
INDIGO CARMINE affects which blood levels in the amniotic fluid?
bilirubin levels
O.DD (optical density Determination) measures _____ levels in ________ pregnancies
bilirubin
RH sensitized
ODD is usually done in What trimesters?
Late 2nd and 3rd
ODD is placed in a brown bottle because?
It is photosensitive
What test looks at lung maturity?
L/S ratio
What are the 2 surfactants of the lungs
Lecithin and Sphingomyelin
What are surfactants responsible for?
Decrease in surface tension in the alveoli of the lungs
Lecithin and Sphingomyelin are fairly equal in the amniotic fluid up to
33 weeks gestation
After 33 weeks ______ increases significantly where ________ remains constant
Lecithin;Sphingomyelin
If the L/S ratio is greater than 2:1 this means?
The lungs are considered mature
L/S test is done in the ____trimester
3rd
L/S is done when ?
Early delivery is elected by doctor or repeat c -Section
Early birth can be caused by
Gestational diabetes High blood pressure PROM Placental insufficiency RH disease
What test is done for polyhydramnios?
Therapeutic amniocentesis
What does Therapeutic amniocentesis help with?
Pressure of the large uterus pressing on abdominal contents causing SOB
Other reasons for Therapeutic amniocentesis
Can occur from Twin to twin transfusion and hydrops
Fluid will reaccumulate within days
What does PUBS stand for?
Percutaneous umbilical blood sampling
What is another name for PUBS?
CORDOCENTESIS*
With the PUBS procedure a needle is put into the umbilical cord __to__cm from placenta insertion
2 to 3
What is usually sampled the umbilical vein or the artery?
Vein
The umbilical vein can be sampled in the?(3)
Liver
Heart
Or free floating
PUBS is usually used after ___weeks to for genetic disorders and blood conditions
18
Indications for PUBS
Chromosomal analysis within 72 hours Fetal blood gas sampling in IUGR fetuses Fetal infections FETAL ANEMIA IN RH SENSITIZATION FETAL BLOOD TRANSFUSION VIA PUBS Treat fetal arrhythmia with medications via PUBS
Risk of PUBS
becoming more rare
Bleeding from puncture site
Infection
rupture of membranes
What does FISH stand for?
Flouresence in Situ Hybridization
What is FISH used for?
looks for how many copies are present for a specific chromosome.
Which chromosomes does FISH look for
Trisomy, 13, 18, 21 x and y
Which has less steps FISH or cytogenetic karotyping?
FISH
FISH can be performed on which 3 things?
fetal blood
amniotic fluid
CVS
is the results of FISH fast or slow?
FAST
When there is a hole in the diaphragm (abdo contents moving into chest cavity pressing on the developing lungs) what is used to fix this?
Diaphragmatic hernia treatment
